Answer:
the answer is 21
Step-by-step explanation:
if one of the factors is 7 and it's between 20 and 30
then it can be 21 or 28
7×3=21 and 7×4=28
now the factors of 21: 1, 3, 7, 21 (4 factors)
the factors of 28: 1, 2, 4, 7, 14, 28 (6 factors)
therfore 21 is the correct answer
